Pickling bath and process for pickling iron and steel



252. COMPOSITJNEQM l4 8 Paltented July 3, 1923.

ifZiTiSH 72am; {zeta (JQQZ/YMI/ I 55' 1 7? UNITED STATES 1% Drawing.

steel, malleable iron, wrought lron, iron alloys as nickel-, chromium-, tungsten-, etc.

steel. V. v

In pickling such iron and iron articles 5 by means of acids and acid substances dissolving iron oxides in order to give the iron a clean or smooth surface the iron and articles from it becomes brittle. In order to prevent this disadvantage the new pickling bath contains besides the acids or acid substances aromatic compounds having a ring nucleus in which several carbon atoms are united with a nitrogen atom. Suitable compounds are chinoline derivatives, as coal tar chinoline, synthetical chinoline, isochinoline, substituted chinoline compounds as acridine, alphanaphthochinoline; beta-naphliochinolinefchinoline yellow, soluble in alcohol or water. Also extracts by means of acids from the fractions containing such bases, obtained in the distillation of coal tar are suitable. One may also use such fractions from'the distillation of coal tar containing such bases. Also the synthetically made products may be added to the pickling bath..- For instance the raw prodnot from the synthetical production of chinoline or naphthochinoline or the molten mass fromthe production of chinoline yel- 40 low may be immediately used without purification. The amounts of the said additions Application filed August 27, 1921.

OTTO VOGEL, OF DUSSELDORF-OBERKASSEL, GERMANY.

PICKLING BATH AND PROCESS FOR PICKLING IRON AND STEEL.

Serial No. 495,954.

may be varied. A favourable action may be obtained even by small additions or solutions oflow percentage; A suitable pickling bath consists of mineral acids, as sulphuric or hydrochloric acid, or organic acids, as acetic acid, or mixtures of mineral and organic acids, or solutions of sodium bisulphate, or mixtures of sodium bisulphate with acids and 1% of chinoline compounds.

The process for pickling consists in that one adds the chinoline compounds to the pickling bath before or during the pickling operation and that one brings the iron or iron article to be treated in this bath until the oxide layer is sufficiently removed. Then one takes the iron from the bath, washes it with water or bases, as lime hydrate, soda lye or such like and water and dries the iron.

I claim 1. Pickling bath for iron consisting in acid substances dissolving iron oxides and aromatic compounds having a nucleus in which several carbon atoms are united with a nitrogen atom.

2. Pickling bath for iron consisting in acid substances dissolving iron oxides and chinoline compounds.

3. The process for pickling iron which consists in bringing iron into a bath containing acid substances dissolving iron oxides and aromatic compounds having a nucleus in which several carbon atoms are united with a nitrogen atom. 7

4'. The process for pickling iron which consists in bringing iron into a bath containing acid substances dissolving iron oxides and chinoline compounds.

In testimony whereof I hereunto aflix my 30 signature.

OTTO VOGEL. 

